1. Field of the Invention
This invention relates to autoloader apparatus for cartridges such as, for example, 3480 style half-inch tape cartridges.
Autoloader apparatus is typically used in automated data storage and retrieval systems for storing large amounts of data on magnetic tape cartridges for example. Such systems generally include a rack for storing the cartridges, a cartridge deck for recording/replaying the cartridges, and means for transferring cartridges between the rack and the deck. A control unit controls operation of the transfer means and the cartridge deck so that the required cartridges are selected, recorded or reproduced as required, and then returned to the rack.
2. Description of the Prior Art
In such autoloader systems, efficient use of space and simplicity of the operating mechanism are always important considerations, and it is desirable for the apparatus to be as compact and efficient as possible.
Autoloader systems are known in which the cartridge rack holds a vertical stack or horizontal row of cartridges, and the transfer means comprises a mechanical hand which grips a cartridge, extracts the cartridge from the rack and then carries the cartridge to the deck for insertion therein. However, on extracting a cartridge from the rack, the mechanical hand, as well as the cartridge, must be moved until the cartridge is clear of the rack before it can be manoeuvred towards the deck. A large amount of operating space is therefore required for the mechanical hand to perform the required movements. Alternatives have been proposed in which a cartridge extracted from the rack is received by a carriage which carries the cartridge towards the deck. Mechanical grippers are mounted in the carriage to grip opposite side edges of a cartridge in the rack, the grippers being provided with conveyor belts to draw the cartridge into the carriage. In operation, the carriage is moved to align the grippers with a cartridge to be extracted, the grippers are then closed on the opposite edges of the cartridge and the conveyor belts activated to convey the cartridge into the carriage. Such an arrangement can save operating space in the direction of extraction of a cartridge from the rack, but the double gripper mechanism is relatively complex, and once a cartridge has been conveyed into the carriage, the grippers must be moved apart so as to clear other cartridges in the rack when the carriage is then moved. This requires additional operating space on either side of the rack. Moreover, the drive mechanism for the grippers is relatively bulky, and when the carriage is aligned with a cartridge at either end of the rack, the drive mechanism projects beyond the end of the rack. Since clearance must be provided for the drive mechanism beyond the ends of the rack, the required operating space is again increased.